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Linear-accelerator X-ray output: a multicentre chamber-based intercomparison study in Australia and New Zealand

  • M. A. Ebert
  • S. J. Howlett
  • K. Harrison
  • D. Cornes
  • C. S. Hamilton
  • J. D. Denham
Scientific Papers

Abstract

This paper describes the process and results of a survey of linear accelerator outputs as part of an Australasian Level III Dosimetry Intercomparison. This study involved the measurement of accelerator output under reference conditions (‘Level I’) with a small-volume ionisation chamber in water for 47 beams at 36 radiotherapy centres using the IAEA TRS 398 dose-to-water protocol. The mean ratio of measured to locally-determined accelerator output was 1.003±0.009 (1 standard deviation) with a range from 0.981 to 1.024. No correlation could be found between output ratio and accelerator type or local output calibration protocol. The small-volume chamber used satisfied most requirements for the study though showed some variation in sensitivity via repeated cross-calibration with a chamber calibrated at a primary standards laboratory.

Key words

TRS 398 radiotherapy audit dosimetry intercomparison 

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References

  1. 1.
    Kron, T., Hamilton, C., Roff, M. and Denham, J.,Dosimetric intercomparison for two Australasian clinical trials using an anthropomorphic phantom, Int J Radiat Oncol Biol Phys, 52(2): 566–79, 2002.PubMedGoogle Scholar
  2. 2.
    Izewska, J., Georg, D., Bera, P., Thwaites, D., Arib, M., Saravi, M., Sergieva, K., Li, K., Yip, F.G., Mahant, A.K. and Bulski, W.,A methodology for TLD postal dosimetry audit of high-energy radiotherapy photon beams in non-reference conditions, Radiother Oncol, 84(1): 67–74, 2007.CrossRefPubMedGoogle Scholar
  3. 3.
    IAEA,Lessons learned from accidental exposures in radiotherapy, International Atomic Energy Agency, Safety Report Series N17, Vienna.Google Scholar
  4. 4.
    Bentzen, S.M., Bernier, J., Davis, J.B., Horiot, J.C., Garavaglia, G., Chavaudra, J., Johansson, K.A. and Bolla, M.,Clinical impact of dosimetry quality assurance programmes assessed by radiobiological modelling of data from the thermoluminescent dosimetry study of the European Organization for Research and Treatment of Cancer, Eur J Cancer, 36(5): 615–20, 2000.CrossRefPubMedGoogle Scholar
  5. 5.
    IAEA. IAEA TLDPostal Dose Audit Service. http://wwwnaweb. iaea.org/nahu/dmrp/tld.asp. 2007Google Scholar
  6. 6.
    Izewska, J., Andreo, P., Vatnitsky, S. and Shortt, K.R.,The IAEA/WHO TLD postal dose quality audits for radiotherapy: a perspective of dosimetry practices at hospitals in developing countries, Radiother Oncol, 69(1): 91–7, 2003.CrossRefPubMedGoogle Scholar
  7. 7.
    Izewska, J., Bera, P. and Vatnitsky, S.,IAEA/WHO TLD postal dose audit service and high precision measurements for radiotherapy level dosimetry. International Atomic Energy Agency/World Health Organization, Rad Prot Dosim, 101(1–4): 387–92, 2002.Google Scholar
  8. 8.
    Izewska, J., Gajewski, R., Gwiazdowska, B., Kania, M. and Rostkowska, J.,TLD postal dose intercomparison for megavoltage units in Poland, Radiother Oncol, 36(2): 143–52, 1995.CrossRefPubMedGoogle Scholar
  9. 9.
    Svensson, H., Hanson, G.P. and Zsdanszky, K.,The IAEA/WHO TL dosimetry service for radiotherapy centres 1969–87, Acta Oncologica, 29(4): 461–7, 1990.CrossRefPubMedGoogle Scholar
  10. 10.
    Ferreira, I.H., Dutreix, A., Bridier, A., Chavaudra, J. and Svensson, H.,The ESTRO-QUALity assurance network (EQUAL), Radiother Oncol, 55(3): 273–84, 2000.CrossRefPubMedGoogle Scholar
  11. 11.
    Hansson, U., Johansson, K.A., Horiot, J.C. and Bernier, J.,Mailed TL dosimetry programme for machine output check and clinical application in the EORTC radiotherapy group, Radiother Oncol, 29(2): 85–90, 1993.CrossRefPubMedGoogle Scholar
  12. 12.
    Roue, A., Van Dam, J., Dutreix, A. and Svensson, H.,[The EQUAL-ESTRO external quality control laboratory in France], Cancer Radiotherapie, 8 Suppl 1: S44–9, 2004.Google Scholar
  13. 13.
    Nisbet, A. and Thwaites, D.I.,A dosimetric intercomparison of electron beams in UK radiotherapy centres, Phys Med Biol, 42(12): 2393–409, 1997.CrossRefPubMedGoogle Scholar
  14. 14.
    Nisbet, A., Thwaites, D.I. and Sheridan, M.E.,A dosimetric intercomparison of kilovoltage X-rays, megavoltage photons and electrons in the Republic of Ireland, Radiother Oncol, 48(1): 95–101, 1998.CrossRefPubMedGoogle Scholar
  15. 15.
    Thwaites, D.I., Williams, J.R., Aird, E.G., Klevenhagen, S.C. and Williams, P.C.,A dosimetric intercomparison of megavoltage photon beams in UK radiotherapy centres, Phys Med Biol, 37(2): 445–61, 1992.CrossRefPubMedGoogle Scholar
  16. 16.
    Venables, K.,The national trials QA centre. Who are we, what we do, and how we can help you, Scope, 15: 10–15, 2006.Google Scholar
  17. 17.
    Huntley, R. and Izewska, J.,The 1998 Australian external beam radiotherapy survey and IAEA/WHO TLD postal dose quality audit, Aust Phys Eng Sci Med, 23(1): 21–9, 2000.Google Scholar
  18. 18.
    Amies, C., Rose, A., Metcalfe, P. and Barton, M.,Multicentre dosimetry study of mantle treatment in Australia and New Zealand, Radiother Oncol, 40(2): 171–80, 1996.CrossRefPubMedGoogle Scholar
  19. 19.
    Delaney, G., Beckham, W., Veness, M., Ahern, V., Back, M., Boyages, J., Fox, C., Graham, P., Jacob, G., Lonergan, D., Morgan, G., Pendlebury, S. and Yuile, P.,Three-dimensional dose distribution of tangential breast irradiation: results of a multicentre phantom dosimetry study, Radiother Oncol, 57(1): 61–8, 2000.CrossRefPubMedGoogle Scholar
  20. 20.
    Kron, T., Barnes, K. and O’Brien, P.,Multicentre dosimetric comparison of photon-junctioning techniques in head and neck radiotherapy, Aust Radiol, 47(3): 289–94, 2003.CrossRefGoogle Scholar
  21. 21.
    Cox, M., Huntley, R. and Webb, D.,A TLD therapy dosimetry quality assurance program for Australia — Results 2002–2003, Aust Phys Eng Sci Med, 27(4): 264–265, 2004.Google Scholar
  22. 22.
    IAEA,Absorbed dose determination in external beam radiotherapy: An international code of practice for dosimetry based on standards of absorbed dose to water, International Atomic Energy Agency, Technical Report Series No. 398, Vienna.Google Scholar
  23. 23.
    IAEA,Absorbed dose determination in photon and electron beams: An international code of practice, International Atomic Energy Agency, Technical Report Series No. 277, Vienna.Google Scholar
  24. 24.
    Ebert, M.A., Harrison, K., Cornes, D., Howlett, S., Joseph, D.J., Kron, T., Hamilton, C.S. and Denham, J.W.,A comprehensive Australasian multi-centre dosimetric intercomparison — issues, logistics and recommendations, Journal of Medical Imaging and Radiation Oncology, In press, 2008.Google Scholar
  25. 25.
    Ebert, M.A., Harrison, K., Denham, J.W., Cornes, D., Howlett, S. and Hamilton, C.,QA of conformal radiotherapy for multi-centre radiotherapy trials in Australasia, inInternational Conference on Quality Assurance and New Technologies in Radiation Medicine. 2006, IAEA: Vienna, Austria.Google Scholar
  26. 26.
    Followill, D.S., Tailor, R.C., Tello, V.M. and Hanson, W.F.,An empirical relationship for determining photon beam quality in TG-21 from a ratio of percentage depth doses, Medical Physics, 25: 1202–1205, 1998.CrossRefPubMedGoogle Scholar
  27. 27.
    Castro, P., Garcia-Vicente, F., Minguez, C., Floriano, A., Sevillano, D., Pérez, L. and Torres, J.J.,Study of the uncertainty in the determination of the absorbed dose to water during external beam radiotherapy calibration, Journal of Applied Clinical Medical Physics, 9(1): 70–86, 2008.CrossRefGoogle Scholar
  28. 28.
    Millar, M., Cramb, J., Das, R., Ackerly, T., Brown, G., Webb, D.,ACPSEM Position Paper Recommendations for the Safe Use of External Beams and Sealed Brachytherapy Sources in Radiation Oncology, Aust Phys Eng Sci Med, 20(3): 1–35, 1997.Google Scholar
  29. 29.
    Butler, D.J., Palmans, H. and Webb, D.V.,Shift in absorbed dose for megavoltage photons when changing to TRS-398 in Australia, Aust Phys Eng Sci Med, 28(3): 159–164, 2005.CrossRefGoogle Scholar
  30. 30.
    Wittkämper, F.W., Mijnheer, B.J. and van Kleffens, H.J.,Dose intercomparison at the radiotherapy centres in The Netherlands. 1. Photon beams under reference conditions and for prostatic cancer treatment, Radiother Oncol, 9(1): 33–44, 1987.CrossRefPubMedGoogle Scholar
  31. 31.
    Al-Mokhlef, J.M. and Noori, N.,Quality assurance study for dosimetry of radiation therapy equipment in Saudi Arabia, Annals Of Saudi Medicine, 23(3–4): 148–151, 2003.PubMedGoogle Scholar
  32. 32.
    Huntley, R.B. and Nette, H.P.,International Atomic Energy Agency/World Health Organisation TLD radiotherapy dosimetry intercomparison, Aust Phys Eng Sci Med, 16(1): 44–8, 1993.Google Scholar
  33. 33.
    Davis, B. and Faessler, P.,Quality audit of megavoltage radiotherapy units: intercomparison of dose at a reference point using a mailed TL-dosimetry system, Radiother Oncol, 28(1): 79–81, 1993.CrossRefPubMedGoogle Scholar
  34. 34.
    Dutreix, A., Derreumaux, S., Chavaudra, J. and van der Schueren, E.,Quality control of radiotherapy centres in Europe: beam calibration, Radiother Oncol, 32(3): 256–264, 1994.CrossRefPubMedGoogle Scholar
  35. 35.
    Schiefer, H., Seelentag, W. and Stucki, G.,Ein nationaler Dosimetrievergleich durch Postversand von TLDs. Swiss Society of Radiobiology and Medical Physics, 2001. http://www.sgsmp.ch/annrepA1.htmGoogle Scholar
  36. 36.
    Aguirre JF, T.R., Ibbott G, Stovall M, Hanson WF.Thermoluminscenence dosimetry as a tool for the remote verification of output for radiotherapy beams: 25 years of experience. inProceedings of an International Symposium on Standards and Codes of Practice in Medical Radiation Dosimetry. Proceedings of an International Symposium on Standards and Codes of Practice in Medical Radiation Dosimetry. Vienna: IAEA, 2002.Google Scholar
  37. 37.
    Kroutilíková, D., Novotný, J. and Judas, L.,Thermoluminescent dosimeters (TLD) quality assurance network in the Czech Republic, Radiother Oncol, 66(2): 235–244, 2003.CrossRefGoogle Scholar

Copyright information

© Australasian College of Physical Scientists and Engineers in Medicine 2008

Authors and Affiliations

  • M. A. Ebert
    • 7
    • 1
  • S. J. Howlett
    • 2
  • K. Harrison
    • 3
  • D. Cornes
    • 4
  • C. S. Hamilton
    • 5
  • J. D. Denham
    • 3
    • 6
  1. 1.School of PhysicsUniversity of Western AustraliaPerthAustralia
  2. 2.Australasian College of Physical Scientists and Engineers in MedicineMelbourneAustralia
  3. 3.Department of Radiation OncologyCalvary Mater NewcastleNewcastleAustralia
  4. 4.Trans-Tasman Radiation Oncology GroupCalvary Mater NewcastleNewcastleAustralia
  5. 5.Heidelberg Repatriation HospitalVictoriaAustralia
  6. 6.School of Medicine and Population HealthUniversity of NewcastleNewcastleAustralia
  7. 7.Department of Radiation OncologySir Charles Gairdner HospitalNedlandsAustralia

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